Objective: To formulate once daily capsule filled with multiple unit mucoadhesive sustain release (SR) mini tablets of bosentan prepared using combination gelucire 43/01 and hydroxypropyl methyl cellulose (HPMCK4M), sodium carboxymethyl cellulose (NaCMC) and chitosan to sustain drug release for 24 h.Methods: The mini tablets were prepared by melt granulation technique using gelucire 43/01 as meltable hydrophobic release retardant. The polymers such as hydroxypropyl methylcellulose (HPMCK4M), sodium carboxymethyl cellulose (NaCMC) and chitosan were added as release modulators and mucoadhesives. The physical mixture of drug and excipient were subjected Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) for evaluation of drug-polymer interaction. Mini tablets were evaluated for mucoadhesive strength, in vitro drug release, swelling index and percentage of hydration. The optimized mini tablets of formulation F23 were filled into zero sizes hard gelatin capsule.Results: The release of bosentan from gelucire 43/01 based sustain release mini tablets extended drug release for 24 h with an initial burst release of more than 32 %. Incorporation of NaCMC, HPMCK4M and chitosan into the mini tablets controlled initial burst release with mucoadhesion.Conclusion: Hence mini tablets prepared with a combination of gelucire 43/01 (release retardant) and NaCMC (release modulator and mucoadhesive polymer) filled into zero sizes hard gelatin capsule can be used to formulate once daily formulation of bosentan
